. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. P. Jacksoni. Fig. 175. Polygyra Troostiana, Lea. Shell rimately umbilicated, discoidal, slightly convex above, flat- tened below, obtusely carinated, with separated strong rib-like striae throughout,1 hirsute, russet horn-color; spire not much ele- vated ; whorls 5^, flattened, the last more convex, descending at the aperture, grooved behind the peristome, with a smoother bulge, below plane, widely rimated, and ending in a small umbili- cus ; aperture oblique, subreniform, very much contracted, far Q^^ within on the b
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. P. Jacksoni. Fig. 175. Polygyra Troostiana, Lea. Shell rimately umbilicated, discoidal, slightly convex above, flat- tened below, obtusely carinated, with separated strong rib-like striae throughout,1 hirsute, russet horn-color; spire not much ele- vated ; whorls 5^, flattened, the last more convex, descending at the aperture, grooved behind the peristome, with a smoother bulge, below plane, widely rimated, and ending in a small umbili- cus ; aperture oblique, subreniform, very much contracted, far Q^^ within on the base of the outer whorl with a small, detached, P. Troostiana, erect, rounded tubercle; peristome white, thickened, continuous, enlarged. ends approached, joined by an excavated, emarginate, somewhat 1 Some of the striae extend over the carina on to the base of the shell without being car ried into the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Harvard University. Museum of Comparative Zoology. Cambridge, Mass. : The Museum
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Keywords: ., bookauthorha, bookcentury1800, bookdecade1870, booksubjectzoology
